1. Field of the Invention
The present invention concerns a locking device.
2. Description of the Related Art
The openable top of an open automobile usually consists of a folding top framework mechanism and a resilient covering thereupon, the so-called top fabric. In its opened position the top is folded up in the space behind the seats, or at another suitable location. When closed, the top is stretched out, covering in the manner of a solid top the passenger space of the car or part thereof. In that instance the top has to be locked with a locking device relative to the body.
In prior art are known, through references U.S. Pat. No. 4,830,425 and DE 1,066,881, locking devices operated by one twisting handle, disposed on a frame rib of the car top. The locking device comprises the following elements, connected to the top framework of the openable car top: a twisting handle, locking elements, locking pins, locking hooks or equivalent, and a transmission interconnecting said locking elements and connecting them with one joint twisting handle for transmitting the turning motion of said handle to the locking elements in order to bring them simultaneously into their open position, respectively their locked position, and a fixing lug connected to the body of the open automobile, arranged to engage the locking element. The transmission comprises draw/pushbars arranged to be movable by means of the twisting handle in a direction which is transverse to the car's longitudinal direction. To the ends of said draw/pushbars are connected slide-type locking elements which in their locked position are secured to the fixing lugs.
The problem embarrassing any design of prior art is that in pushbar operation the turning angle of the locking slides, or hooks, always falls short of 180.degree., and with this no substantial self-retaining feature of the spindle can be achieved.
Another problem associated with locking devices of prior art is that in push/drawbar designs the torque which has to be applied when turning the handle changes throughout the turning motion, and this is not pleasant from the user's point of view.
Pushbar operation is applicable in those instances in which a slide-type locking is used, such as is disclosed in the references cited above, but a design like this poses the further problem that it is difficult therewith to achieve a long pulling motion longitudinally to the car by which a dual advantage would be gained. When closing the canopy top, it would enable adequate tensioning of the top fabric to be achieved with ease. On the other hand the end position of the running-up motion would not have to be as exact as it is required to be in slide-type locking.